63. Упростите выражение: 1) $$\frac{5}{18}c + \frac{7}{24}c - \frac{11}{36}c$$; 2) $$2 \frac{7}{16}y + 3 \frac{5}{20} + 1 \frac{1}{8}y$$.

1) $$\frac{5}{18}c + \frac{7}{24}c - \frac{11}{36}c = (\frac{5}{18} + \frac{7}{24} - \frac{11}{36})c = (\frac{5 \cdot 4}{18 \cdot 4} + \frac{7 \cdot 3}{24 \cdot 3} - \frac{11 \cdot 2}{36 \cdot 2})c = (\frac{20}{72} + \frac{21}{72} - \frac{22}{72})c = \frac{20 + 21 - 22}{72}c = \frac{19}{72}c$$ 2) $$2 \frac{7}{16}y + 3 \frac{5}{20} + 1 \frac{1}{8}y = 2 \frac{7}{16}y + 3 \frac{1}{4} + 1 \frac{1}{8}y = (2 \frac{7}{16} + 1 \frac{1}{8})y + 3 \frac{1}{4} = (2 \frac{7}{16} + 1 \frac{2}{16})y + 3 \frac{1}{4} = 3 \frac{9}{16}y + 3 \frac{1}{4}$$